Task 34 The figure shows the Venturi flow meter,

Task 34 The figure shows a Venturi flow meter through which water flows with a density of p = 1000 kg / m3. The diameter of the cylindrical pipeline D = 20 cm, the diameter of the narrow part of the flow meter d = 16 cm. In the upper part, two piezometers are attached to the Venturi flow meter, the height difference between which is DN = 50cm. In the lower part, a mercury piezometer is connected, the height difference in which is Δh. The density of mercury is 13600 kg/m3. Local pressure losses should be neglected. The water flow mode is turbulent. Identify missing data.